1. Field of the Invention
The present invention relates to polyolefin nanocomposites, and particularly to a method of making high-density polyethylene (HDPE) with titania-iron nanofillers in order to control the molecular weight of the HDPE.
2. Description of the Related Art
Ethylene polymerization is a well-known process, and is conventionally performed using free-radical polymerization, the Zeigler-Natta catalyst technique, the Phillips catalyst technique, the metallocene catalyst technique, and the post-metallocene catalyst technique. Polyolefin nanocomposites are of great interest due to their mechanical and thermal properties. It has been found that addition of nanoparticles, such as titanium dioxide, doped titanium, silicon dioxide, aluminum trioxide and zirconium dioxide, may improve the polymer properties of such composites.
TiO2-filled polymers have been prepared by solution mixing, melt compounding and in situ polymerization. In situ polymerization is considered to be the most promising method, as it provides a homogeneous dispersion of the filler in the polymer matrix. Although TiO2-filled polymers are known, the properties of such composite materials are fixed. It would be desirable to provide a method for doping the titania nanofiller material that permits control over and variation of the overall polymeric properties, such as molecular weight and the associated thermal properties.
Thus, a method of making high-density polyethylene with titania-iron nanofillers solving the aforementioned problems is desired.